Genuine Fujitsu 9378321014 Outdoor Expansion Valve Assembly is the expansion valve in the outdoor unit, metering the refrigerant flow the control board asks for. A failed or sticking valve loses that control, so the system heats or cools poorly, ices up or stops with a fault. A genuine Fujitsu part is made to the same design as the original, so it goes back in the way the outdoor unit was built.